YAEDA VALLEY, Tanzania -- One of the last remaining tribes of hunter-gatherers on the planet is on the verge of vanishing into the modern world.

The transition has been long underway, but members of the dwindling Hadzabe tribe, who now number fewer than 1,500, say it is being unduly hastened by a United Arab Emirates royal family, which plans to use the tribal hunting land as a personal safari playground.

The deal between the Tanzanian government and Tanzania UAE Safaris Ltd. leases nearly 2,500 square miles of this sprawling, yellow-green valley near the storied Serengeti Plain to members of the royal family, who chose it after a helicopter tour.

A Tanzanian official said that a nearby hunting area the family shared with relatives had become "too crowded" and that a member of the Abu Dhabi royal family "indicated that it was inconvenient" and requested his own parcel.

The official, Philip Marmo, called the Hadzabe "backwards" and said they would benefit from the school, roads and other projects the UAE company has offered as compensation.

But dozens of Hadzabe interviewed deep in the scruffy hills surrounding this valley said that while they are ready to modernize, slowly, they were not consulted on the deal, which is a direct threat to their way of life because it involves hunting.

While they have through 50,000 years survived the coming of agriculture, metal, guns, diseases, missionaries, poachers, anthropologists, students, gawking journalists, corrugated steel houses and encroaching pastoral tribes who often impersonate them for tourist money, the resilient Hadzabe, who still make fire with sticks, fear that the safari deal will be their undoing.

"If they are going to come here, we definitely will all perish," said Kaunda, a Hadzabe man who prefers khakis but still hunts with hand-hewn poison arrows. "Our history will die, and the Hadzabe will be swept off the face of the world. We are very much afraid."

Their fear is based on a similar agreement the government struck years ago with another company that resulted in dozens of Hadzabe men being arrested for hunting on tribal land. Three of the men died of illness in the bewildering environment of prison, cut off from the open world, their daily hunting and their diet of herbs, roots and honey. Three others died soon after being released.

"We're not used to that kind of life in jail," said Gudo, an elderly Hadzabe whose best friend, Sumuni, was among those who perished. "Sumuni was my age. Our fathers were friends. We played together, learned how to hunt together," he said, looking away. "I don't want to talk anymore."

A recent meeting in the Yaeda Valley on the issue ended with several Hadzabe men shouting at Tanzanian government officials for ignoring them. One of the men was later charged with disruptive behavior and jailed for several days. Two others who have spoken against the deal said they have been threatened with arrest and are now on the run, moving from hut to hut to elude police.

Others seem prepared to fight an intruder they barely know.

Although the Hadzabe characteristically avoid confrontation by fleeing into the bush, a group of men recently greeted a passing convoy of Land Cruisers with bows drawn.

"I don't even know what an Arab looks like," said Kaunda, who was among them. "Maybe he's black. Maybe he's another color. I don't know. But we are ready to die."

A few groups that advocate on behalf of indigenous peoples are working with the Hadzabe to promote a dialogue with the government and the company, a task that poses its own challenges. The Hadzabe are highly decentralized, living in remote, mobile settlements of two or three families scattered throughout the valley. They are also egalitarian, with no real hierarchy or leadership, and tend to reach decisions by consensus.

Even if the tribe came up with a solution, it remains unclear whether the Tanzanian government or the UAE company would be willing to compromise. Marmo said the Hadzabe -- who until recently had no use for money, organized religion or standard time -- are "the one backwards group in the country."

"We want them to go to school," said Marmo, who is Tanzania's minister for good governance and represents the valley in parliament. "We want them to wear clothes. We want them to be decent."

Messages left with the UAE Embassy in Washington and a company representative were not returned.

The Hadzabe are believed to be the second-oldest people on Earth, and they still hunt and gather as a way of life, if occasionally before audiences of khaki-covered tourists, who flock to northern Tanzania by the thousands.

All live in the Yaeda Valley and surrounding hills, where one of the wanted men, Gonga Petro, lounged against a rock recently and reflected on his difficulties.

"It's very important to go to work and hunt, but now, you can just walk from morning to night and if you're lucky, you might come back with a dik-dik," he sighed, referring to an animal that is embarrassingly small for someone who once slew two zebras, an antelope and a buffalo in a single day. "But there's always an alternative. The baobab. Together with the herbs."

It was morning in his settlement, the four straw huts nearly invisible amid waist-high grass, thorny bushes and thick-trunked baobab trees.

The four children were out gathering fruits and pretending to be frogs. Their mothers sat outside, picking leaves off branches for lunch. Gonga sharpened arrows.

His family and one other moved to the spot three years ago to escape a cholera epidemic, he said, one of a multitude of problems the Hadzabe face.

The Yaeda Valley once teemed with elephants, zebras, antelopes and other animals migrating to the Serengeti Plain, but the wildlife populations have dwindled in recent decades because of heavy poaching and because several farming and cattle-herding tribes have drifted into the area, competing for water and grazing land.

Some Hadzabe have tried to adopt their neighbors' ways, starting small farms. Others have headed to villages to look for jobs. Mostly, the Hadzabe's economy depends on selling wild honey in exchange for something called money, which Gonga once used to roll his cigarettes.

"Money was just papers," he recalled. "It was very strange, because we learned you could take this paper to a shop and get a pen. It was very interesting."

He lit a cigarette, rolled with a piece of newspaper that described a papal visit.

Government efforts over 40 years to forcibly integrate the Hadzabe into modern society have mostly failed. Instead, the Hadzabe seem to have preferred changing at their own pace, adopting bits of modern life over centuries.

A program to move families into a village of metal houses ended with Hadzabe fleeing to the bush after only a few days. "When it rains, those houses make a lot of noise," said Sarah Makungu, who tried them. "In fact, to be honest, we don't want to live in iron corrugated huts, but we would keep our plates and such in there."

The introduction of standard time has also come slowly. "What is the need for time?" Kaunda asked. "You wake up, you get honey. What do you need time for?"

Though some Hadzabe children attend primary and secondary boarding school in the valley, programs to build new schools and provide medical care and water have mostly benefited neighboring tribes and have lured more people to the overpopulated valley.

Missions to spread Christianity have also failed. "We just go to church as if we are pictures," one man said. "Our hearts and minds are not there."

Though the Hadzabe have managed to survive for millennia, Gonga and others said the UAE deal is particularly worrisome because it comes on top of the other pressures they are facing and because the newcomers will be hunting with the support of a government that seems hostile to the tribe's complaints.

"If we had been involved from the beginning, the issue could have been resolved mutually," Gonga said. "We need development, but when things are done this way, it gives us the feeling we are being cheated or used for other people's benefit."

He wondered why this tribe, the Arabs, did not seek his opinions. "Why were we not called upon?" he asked, explaining that he would share a cigarette and talk if they came.

His wife, Veronique, who said she married Gonga not for his hunting skills but because she loved him, answered: "These people knew from the beginning we were nothing. That's why they didn't invite us to their meetings."

It was afternoon, and Gonga got back to work, straightening arrows with his teeth.

Veronique walked with other women into the wiry tangles and green of a thousand different bushes and trees, in search of roots.

The orange sun slipped away. When it was dark, the families talked around a fire under a black sky dusted with stars.

"It's like we have to marry someone we don't know," Gonga said of the deal. "It's like an imposed wife. You have to talk to someone before you have to live with them."

He told some jokes about his encounters with the modern world, such as toilets, which he finds unsanitary and strange.

He did impersonations in a high, shrill voice of various researchers he's met over the years. And he looked up and asked about stories he'd heard of people going to the moon.

"We hear some people were lost in the stars," he said. "Is this true?"